Growth and Yield Curve Preparation and Delivery

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Growth and Yield Curve Preparation and Delivery Powered By Docstoc
					April 2005
Summary No.47             Morice & Lakes Innovative Forest Practices Agreement

                                                    PROJECT SUMMARY
Ecosystem                            Developing and implementing Sustainable Forest Management Plans for both the
Management                   Lakes and Morice Timber Supply Areas is the central objective of the Morice and Lakes Innovative
Forest Productivity       Forest Practices Agreement.The adaptive management cycle and public involvement are both important
                                                          components of this planning process.
Public Involvement

Management                              Growth and Yield
                                  Curve Preparation and Delivery
                          Introduction                                               Objectives
                          Yield curves are used to quantify various timber and       The objectives of the activity are as follows:
                          non-timber values on the land base. The Morice and
                                                                                     • To produce a set of base case curve sets that
                          Lakes Innovative Forest Practices Agreement (M&L
                                                                                       reflect natural stand development and the per-
                          IFPA) is relying on this information to help support the
                                                                                       formance of plantations based on Timber Supply
                          forecasting and reporting of indicators in a number
                                                                                       Review forest management assumptions.
                          of learning scenarios.Yield curves that reflect natural
                          stand development and the performance of plantations       • To produce a set of forest productivity curve sets
                          based on Timber Supply Review (TSR2) management              that provide an insight into the timber and non-
                          assumptions have been developed to support the               timber resource implications of applying revised
                          base case scenario. Special curve sets were developed        estimates of site productivity and various silvicul-
                          to support the forecasting of indicators under three         tural regimes and treatments.
                          scenarios: the forest productivity scenario, the natural
                                                                                     • To produce a set of natural disturbance curve sets
                          disturbance scenario and the recreation scenario.
                                                                                       that mimic natural forest successional pathways
                          The forest productivity scenario curve sets were             in order to assess the timber and non-timber
                          developed based on the Morice base case curve sets           resource implications of managing the land base
                          and additional forest productivity studies and data          using current knowledge of natural ecosystems.
                          that were not incorporated in the last Timber Supply
                                                                                     Additional adjustments were made to yield curves to
                          Review of the Morice Timber Supply Area (TSA).
                                                                                     account for non-recoverable volume losses. The foun-
                          The natural disturbance scenario curve sets were           dations of these adjustments are the projections of
                          developed based on the Morice TSA base case curve          the British Columbia Mountain Pine Beetle (BCMPB)
                          sets and include additional curves to account for          project. The basic method is to apply the BCMPB
                          forest succession in different ecosystem types.            projections in reducing yield curves as precisely as
                                                                                     possible according to a stand’s age, landscape unit, and
   Fraser Lake Sawmills
                                                                                     pine component class.

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Morice & Lakes IFPA Project Summary

Methods                                                                      1. Integration of Silvicultural Treatment Data into the GIS
A variety of yield curve sets were prepared over a two year                  The layers that were added include brushing, fertilization, geneti-
period to support scenario planning in each TSA. The processes               cally improved plantations, juvenile spacing, pruning, seed planning
used to prepare and deliver each set are briefly described below.            units and site preparation.
Additional information on the preparation of each yield curve set
is available from the IFPA website at              2. Developing the Main Lookup Table used for Growth &
                                                                             Yield Curve Generation
                                                                             The forest productivity scenario used assumptions that were
Base Case Yield Curve Sets                                                   applied based on biogeoclimatic zone, subzone, variant and site
The base case yield curve sets were the first curve sets to be               series combinations. Therefore, the lookup table is based on the
developed. They were required for modeling the base case sce-                resultant overlay and incorporates all additional necessary data
narios for each TSA. The Variable Density Yield Prediction (VDYP)            including the forest inventory layer, the PEM layer and all the silvi-
model was used for estimating timber attributes in natural stands.           cultural treatments.
The Table Interpolation Program for Stand Yields (BatchTIPSY)
model was used for estimating timber and non-timber attributes in 3. Development of Yield Curves
managed stands.                                                     Polygon specific curves (i.e. a curve for every forested polygon)
                                                                    were developed. The majority of the assumptions were incorpo-
The initial phase of the base case curve sets involved updating the rated into the main lookup table. The curves were assigned a natu-
forest inventory data to better reflect the status of the land base ral, managed or a future managed status and all attributes required
as of August 31, 2001. Using the silviculture survey measurement    to produce the base line curves were included in the lookup table.
data from ISIS (the standard Ministry of Forests reporting tool for Due to the large size of the datasets, each unique combination of
silviculture information) and some general assumptions, the Non-    input parameters required for the growth and yield models were
Satisfactory Restocked (NSR) stands within the forest inventory     grouped together for each type of curve: natural, managed and
were updated. This inventory update process was completed for       future managed. Once grouped, each curve was given a unique
the Lakes TSA in September 2004 to better reflect the status of     table number and related back to the main lookup table.
the Lakes TSA landbase to April 2004.
The second phase of the base case curve sets involved the genera-            Natural Succession Yield Curve Sets
tion of a curve set for every stand. Additionally, curve sets were    The natural disturbance curve sets are required for modeling the
produced for each analysis unit, as defined in the TSR document.      natural disturbance scenario. The intention of the curves is to
Polygon specific curves (i.e. a curve for every forested polygon)     mimic natural succession on the landbase through the use of suc-
and analysis unit curves (i.e. an area-weighted curve for each analy- cessional pathway diagrams that describe the forest succession and
sis unit) were developed. Due to the large sizes of the datasets, the the impacts of natural disturbances in different ecosystem types.
datasets were grouped by the unique attributes that were required Each successional pathway diagram contains the following informa-
by the growth & yield models. The relationships were maintained       tion:
between the unique input values and the individual forest inven-      • Biogeoclimatic description (including site series)
tory polygons. This same procedure was performed for all the
yield curve sets that were developed for this project.                • Leading and secondary species
                                                                      • Transition times between each class (defined as the number of
Forest Productivity Yield Curve Sets                                     years required to move from one class to the next)
The forest productivity curve sets are required for modeling the             The steps involved in creating these curves sets include:
forest productivity learning scenarios in each TSA. The yield curves
for the forest productivity scenario were developed based on base            1. Creation of Successional Pathway Diagrams
case curves and additional forest productivity studies and data.             The intention was to use the successional pathways developed
There were a number of issues being modeled, and many of the                 during several vegetation dynamics workshops held for the Morice
issues required increased resolution of the resultant file, so more          and Lakes IFPA. The results of these workshops were summarized
data was integrated including spatially identifying areas that were          in the document “Vegetation Pathway Diagrams for the Morice
planted with genetically improved stock and incorporating the spa-           and Lakes Innovative Forest Practices Agreement” produced by
tial locations of silviculture treatments. The intention of the forest       ESSA Technologies Ltd. However, after reviewing the document
productivity curve set is to integrate various issues that would             and comparing the pathways to the landbases for each TSA, it was
provide an insight into the growth potential of different applied sil-       realized that the pathways were too generic in nature to use. In
vicultural treatments or where current silvicultural knowledge was           fact, each of the landbases contained biogeoclimatic descriptions
applied. The steps involved in creating these curves sets include:           and species codes that did not have pathways developed. Because

Morice & Lakes IFPA Project Summary

of this inability to use the existing document, it was decided to
create new pathways, which would explicitly cover both landbases.
                                                                            Discussion and Conclusions
These pathways were developed by Ardea Biological Consulting.        The IFPA analysis is relying heavily on these growth and yield curve
Ardea reviewed all combinations of biogeoclimatic variant, site      sets to support the modelling of a variety of resource values under
series, leading species, secondary species and age contained within  a range of alternate management strategies. Many of the innova-
the two landbases and developed pathways based on these criteria.    tive management practices proposed for the IFPA will be assessed
                                                                     based on the use of this information. This product is a good exam-
2. Assignment of Successional Pathways to each Landbase ple of cooperation between IFPA participants. The end result is a
All of the work performed for the natural disturbance yield curve series of innovative growth and yield projections that facilitate the
development is based on work completed for the base case             modeling and analysis of innovative forest management practices.
curves. Successional pathways were assigned to each resultant
landbase using the following criteria: biogeoclimatic zone, subzone,
variant, site series, leading species; secondary species, and age.          Recommendations
3. Creation of Successional Pathway Yield Curves                            The following recommendation stems from the development of
These are pathways boxes, whose combination of BEC variant, site            the growth and yield curve sets:
series, species and age were found on each landbase. Note that              • That the methodologies used to develop these yield curve
not all of the boxes contained within a successional pathway were             sets be applied on other management units in the province to
found on the landbase. The missing boxes tended to be primarily               further enhance the current approaches to sustainable forest
the early or late successional boxes. These curves were created by            management.
area weighting all the natural base case curves that fell within each
of the pathway boxes on each landbase. Area weighting was done
for both the natural base case inputs and outputs.                          Contacts
                                                                            For more information, contact:
Adjustments for Mountain Pine Beetle Non-                                   Dwight Crouse
Recoverable Volume Losses                                                   Resource Analysis Department Manager, Tesera Systems Inc.
Consistent with the IFPA approach of carrying high resolution,              PO Box 1078, Cochrane, AB, T4C 1B1
stand specific yield-functions, these epidemic related volume loss          (w) 403 932-0446, (f) 403 932-9395
adjustments were implemented at the highest resolution sup-                 Email:
ported by the available data. Stands are allowed to increase in
volume following epidemic induced losses according to rates of              Carol Ann Crouse, RPF
growth previously determined for those stands. The projected                Resource Analyst, Tesera Systems Inc.
proportion of residual live pine moderates those growth rates. For          PO Box 1078, Cochrane, AB, T4C 1B1
strata with some pine component, the pine component is assumed              (w) 403 932-0445, (f) 403 932-9395
to remain constant prior to epidemic loss adjustments being made.           Email:
The Mountain Pine Beetle (MPB) epidemic ends when the BCMPB
project’s projections end in 2013. Beetle killed pine volume dead
no longer than 5 years is viable for saw-logs and is added back to
the yield function.
                                                                            Dwight Scott Wolfe of Tesera Systems, Inc. wrote this summary
                                                                            with technical assistance provided by Dwight Crouse, and Carol Ann
Results                                                                     Crouse. Layout and editing by Ritchie Morrison of Tetrad Communi-
The procedures outlined above resulted in the preparation of                cations.
three types of curve sets. Additional documents describing the
data inputs and assumptions that went into developing these curve
sets are available from the Morice and Lakes IFPA. They include:
• The M&L IFPA Information Package
• Base Case Yield Curves (Morice TSA) – March 2003
• Base Case Yield Curves (Lakes TSA) – March 2003
• Forest Productivity Scenario Yield Curves (Morice TSA) – April
• Ecosystem Scenario Yield Curves (Morice TSA) – April 2004
• Forest Productivity Scenario Yield Curves (Lakes TSA) – Febru-
  ary 2005
• Ecosystem Scenario Yield Curves (Lakes TSA) – January 2005

Morice & Lakes IFPA Project Summary

                                          For More
                                          For more information on the Morice & Lakes IFPA,
                                          please contact:
                                                  Jim Burbee, RPF, IFPA Manager
                                                  c/o Tweedsmuir Forest Ltd.
                                                  3003 Riverview Road
                                                  Prince George, B.C. V2K 4Y5
                                                  Tel: 250-564-1518



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